feat: ✨ convert to api and rewrite ui

frontend/src/utils/datetime.ts

@@ -0,0 +1,23 @@
+/** Parse API timestamps (GMT strings, ISO, or naive UTC) for local display. */
+export function parseApiTimestamp(ts?: string | null): Date | null {
+  if (!ts) return null;
+  const trimmed = ts.trim();
+  if (!trimmed) return null;
+
+  // RFC/GMT strings from Flask/MySQL — parse as-is
+  if (/GMT|Z|[+-]\d{2}:\d{2}$/.test(trimmed)) {
+    const d = new Date(trimmed);
+    if (!Number.isNaN(d.getTime())) return d;
+  }
+
+  // Naive datetime — treat as UTC
+  const normalized = trimmed.includes("T") ? trimmed : trimmed.replace(" ", "T");
+  const d = new Date(normalized.endsWith("Z") ? normalized : `${normalized}Z`);
+  return Number.isNaN(d.getTime()) ? null : d;
+}
+
+export function formatLocalTime(ts?: string | null, fallback = "—"): string {
+  const d = parseApiTimestamp(ts);
+  if (!d) return ts?.trim() || fallback;
+  return d.toLocaleString();
+}